While I don't disagree with your position that you wish a toggle to simply work in one place, I just tested eight of my applications, and none of those have a toggle that works the way you describe: click once, it shows, click again, it hides. At best, each time I click on these icons, they either show the screen, or they pop up a menu. That doesn't typically go away when I hit the icon again.

The ONLY program I have that indicates that behaviour happens when I click on the system clock. That brings up a calendar on the first click, and removes it on the second.

Of the applications I have running now, described behaviour is present for:- ResophNotes (notes organizer)- Miranda-NG (messenger)- CopyQ (clipboard manager)- Mahou (layout switcher, even though it has no real need in this)

There are other apps that I wish to behave in this way but don't bring into view as frequently to be bothered much.

Oh, and taskbar icons behave this way most of the time by design.Obviously, it might not be a natural fit for every tray icon, but for a certain category of apps, to which Voicemeeter and Marco Buttons belong, it is a desireable behaviour.